The invention relates to a method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system, and more particularly to a rapid and whole-scale test method which utilizes standard sets of test devices to screen and further locate possible wiring swap in the hi-fix structure.
In the industry of testing electronic devices, one of efficient methods is the one which applies a simultaneous multi-electronic device test system to carry out target testing automatically simultaneously upon batches of electronic devices. Such a simultaneous multi-electronic device test system can be usually seen as a testing dynamic test handler, a memory test system, a silicon-on-chip test system, a liquid crystal display driver test system, a radio frequency integrated circuit test system, or the like.
In any test system mentioned above, the test system generally has a control unit to operate several test heads, and each test head further includes a hi-fix structure. The hi-fix structure includes a plurality of socket slots arranged typically in an array pattern. Each socket slot is used to receive or mount an electronic device for testing, or a so called device under test (DUT).
Referring to FIG. 1, a typical test head of a conventional simultaneous multi-electronic device test system is shown. In the test head 1, a performance board 3, a hi-fix structure 5 and a plurality of socket slot 51 are constructed in a bottom-to-top layer order. Generally speaking, array patterns for arranging the socket slots 51 on the hi-fix structure 5 vary from manufacturer to manufacturer and also from system to system. As shown in FIG. 2, a top view of a typical array pattern for the socket slots 51 of the hi-fix structure 5 is schematically illustrated. In the N×M array pattern, a total number of N×M socket slots 51, labeled from TS[1] to TS[NM], are shown. While in testing, N×M electronic devices (not shown in the figure) are automatically and simultaneously transferred onto or removed from the hi-fix structure 5, in which each electronic device is targeted to a respective socket slot 51.
Referring now to FIG. 3, a cross-sectional view along line a—a of FIG. 1 is shown. It is seen that a socket board 50 for receiving leads of electronic device is sandwiched between the socket slot 51 and the hi-fix structure 5. Also, a number of connecting cables 53 for engaging with respective leads of the electronic device are located to extend from the socket board 50 to the performance board 3.
Electric conjunction among the electronic device 10 having P leads, the hi-fix structure 5 and the performance board 3 is schematically shown in FIG. 4. Each connecting cable 53 inside the hi-fix structure 5 is applied to connect electrically a respective one of the leads labeled from L(1) to L(P) and extending from the lead side 101 of the electronic device 10 to a respective predetermined location on the performance board 3. In FIG. 4, normal or correct wiring of the connecting cables 53 among the electronic devices 10, the hi-fix structure 5 and the performance board 3 are illustrated by the dashed lines.
In case that the wiring in the hi-fix structure cannot present a normal state as described in FIG. 4, the testing performed by the test head having the hi-fix structure would be definitely incorrect. Practically, possibility of mis-wiring or, say, wiring swap in the hi-fix structure is not rare, and the existence of such a wiring swap does cause real and not-easy-to-be-detected problems in the application of the simultaneous multi-electronic device test system. Referring now to FIG. 5, a comparison to the FIG. 4 is illustrated to present a typical wiring swap in the hi-fix structure 5. As shown, cables 53′ represented by solid lines (correct wiring by dashed lines also presented for reference purpose) inside the hi-fix structure 5 corresponding to the leads L(k) and L(1) of the electronic device 10 are swapped. It is obvious that the hi-fix structure 5 having the wiring swap in FIG. 5 will lead to inaccurate testing results.
In some cases, fortunately, the wiring swap in the hi-fix structure can be detected and fixed by the manufacturer during the quality control session, or can be detected during the pilot run in the application field. The wiring swap in the hi-fix structure exists in the simultaneous multi-electronic device test system during its assembly stage in the manufacturer, but an indication of the wiring swap problem usually rises at the moment when a field engineer questions the test results after a substantial period of usage. Under such a situation, the damage caused by the test system having the wiring swap problem may already be significant.
In the art, in case that a wiring swap is encountered, substantial time and labor are usually required for locating and further correcting the swapped cables. Generally, to avoid time wasted for the shipment between the user end and the manufacturer, the maintenance is usually carried out in the application field, i.e., at the user end. The maintenance targeted to a possible wiring swap includes shutting-down of the test system, disassembling of the test head as well as the hi-fix structure, the connection testing cable by cable, re-assembling, and a final test run to examine if there is another wiring swap. Notably, the maintenance described above is inefficient.
Empirically, wiring swap in the hi-fix structure usually cannot be resolved in a routine or standard maintenance. The reason is that various cables exist in a limited space inside the hi-fix structure, which significantly complicates the pinpointing of all swapped cables. For example, in a hi-fix structure with N×M socket slots, the number of connecting cables inside the hi-fix structure would be N×M×P if each socket slot is designed to receive an electronic device with P leads. Therefore, verification upon each connecting cables is a tedious and labor-intensive task.